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Most residential DIYers who venture into installing metal stud walls go only so far as to use steel studs for partition walls that don’t bear loads and don’t need insulation. If you also want eventually to try building an exterior wall, you’ll need steel studs in the heavier 16 to 18 gauge range -- the ones rated for interior walls are too flimsy -- and a way to deal with the thermal conductivity of steel. The California Energy Commission reports that steel studs conduct 10 times as much heat as a wood stud -- so insulation becomes of paramount importance.

1

Run continuous beads of acoustical sealant on the exterior side of the top and bottom tracks of the wall by squeezing it out of a tube using a caulking gun. Add dabs of sealant on the edges of the studs as well, spaced every 9 inches approximately. Press the vapor barrier against the sealant to enclose the wall.

2

Install a 1-inch-thick thermal break such as a polyisocyanurate board, also called “blue board,” on top of the vapor barrier. Push a 3-inch screw through a large, 2-inch plastic washer, designed to hold the thick but somewhat fragile board in place. Screw through the blue board at each corner and wherever the top and bottom edges cross a metal stud. This step also locks the vapor barrier in place.

3

Keep fiberglass batt insulation out of the stud cavities of the exterior wall to avoid potential moisture buildup and thermal “shorts,” which occur as the fiberglass wicks cold from the steel to the interior drywall. Cover the wall with 4-inch brick veneer or a similar covering, leaving an inch or two of air gap between the veneer and the blue board.

4

Install specially designed fiberglass batt insulation in metal stud walls in basements, where they provide more value than in exterior above-grade walls. Look for insulation designed for commercial buildings, which will be a full 16 inches wide, as opposed to narrower 15-inch insulation placed in the cavities between residential wooden studs. This insulation is stiffer than regular wood-stud batts and stands up on its own. Simply cut the top to fit the height of your wall, using a 2-by-4 to provide a straight edge and a utility knife. Tuck the top and bottom edges into the tracks. Tuck one side edge into the “C” shape of the metal stud facing the stud cavity in an open position. This stiff batt will remain in place, with support on three sides.

Things You Will Need

Acoustical sealant

Caulking gun

Vapor barrier

1-inch polyisocyanurate boards

3-inch screws

2-inch plastic washers

Drill with driver set

Brick veneer

16-inch wide commercial fiberglass batts

2-by-4

Utility knife

Tip

Other options for interrupting the conduction of heat out of your house include spacers to isolate the sheathing from the studs and installing foam-covered steel studs.

About the Author

An award-winning writer and editor, Rogue Parrish has worked at the Washington Post, the Baltimore Sun and at newspapers from England to Alaska. This world adventurer and travel book author, who graduates summa cum laude in journalism from the University of Maryland, specializes in travel and food -- as well as sports and fitness. She's also a property manager and writes on DIY projects.